Android studio 在android studio工具栏上单击图标时以片段形式提供动作

我一直试图在单击工具栏上的图标时执行操作，但我得到一个空异常。我不知道原因是什么

我的代码在片段中

public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.activity_home_fragment, container, false);
    toolbar = (Toolbar)  v.findViewById(R.id.toolbar);
    ((AppCompatActivity)getActivity()).setSupportActionBar(toolbar);
    toolbar.setOnMenuItemClickListener(new Toolbar.OnMenuItemClickListener() {
        @Override
        public boolean onMenuItemClick(MenuItem item) {
            switch (item.getItemId()) {
                case R.id.toolbar_search:

                    // do what ever you want here
            }
            return true;
        }
    });

我尝试过一些解决方案，比如

但这对我不起作用

错误

java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.acadazone/com.example.acadazone.StudentDashboardActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void androidx.appcompat.widget.Toolbar.setOnMenuItemClickListener(androidx.appcompat.widget.Toolbar$OnMenuItemClickListener)' on a null object reference
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2697)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2771)
    at android.app.ActivityThread.access$900(ActivityThread.java:177)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1432)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:135)